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1ika
From Proteopedia
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[[Image:1ika.gif|left|200px]] | [[Image:1ika.gif|left|200px]] | ||
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'''STRUCTURE OF ISOCITRATE DEHYDROGENASE WITH ALPHA-KETOGLUTARATE AT 2.7 ANGSTROMS RESOLUTION: CONFORMATIONAL CHANGES INDUCED BY DECARBOXYLATION OF ISOCITRATE''' | '''STRUCTURE OF ISOCITRATE DEHYDROGENASE WITH ALPHA-KETOGLUTARATE AT 2.7 ANGSTROMS RESOLUTION: CONFORMATIONAL CHANGES INDUCED BY DECARBOXYLATION OF ISOCITRATE''' | ||
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Structure of isocitrate dehydrogenase with alpha-ketoglutarate at 2.7-A resolution: conformational changes induced by decarboxylation of isocitrate., Stoddard BL, Koshland DE Jr, Biochemistry. 1993 Sep 14;32(36):9317-22. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/8369301 8369301] | Structure of isocitrate dehydrogenase with alpha-ketoglutarate at 2.7-A resolution: conformational changes induced by decarboxylation of isocitrate., Stoddard BL, Koshland DE Jr, Biochemistry. 1993 Sep 14;32(36):9317-22. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/8369301 8369301] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
| - | [[Category: Isocitrate dehydrogenase (NADP(+))]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Junior, D E.Koshland.]] | [[Category: Junior, D E.Koshland.]] | ||
[[Category: Stoddard, B L.]] | [[Category: Stoddard, B L.]] | ||
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 20:05:43 2008'' | |
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Revision as of 17:05, 2 May 2008
STRUCTURE OF ISOCITRATE DEHYDROGENASE WITH ALPHA-KETOGLUTARATE AT 2.7 ANGSTROMS RESOLUTION: CONFORMATIONAL CHANGES INDUCED BY DECARBOXYLATION OF ISOCITRATE
Overview
The structure of the isocitrate dehydrogenase (IDH) complex with bound alpha-ketoglutarate, Ca2+, and NADPH was solved at 2.7-A resolution. The alpha-ketoglutarate binds in the active site at the same position and orientation as isocitrate, with a difference between the two bound molecules of about 0.8 A. The Ca2+ metal is coordinated by alpha-ketoglutarate, three conserved aspartate residues, and a pair of water molecules. The largest motion in the active site relative to the isocitrate enzyme complex is observed for tyrosine 160, which originally forms a hydrogen bond to the labile carboxyl group of isocitrate and moves to form a new hydrogen bond to Asp 307 in the complex with alpha-ketoglutarate. This triggers a number of significant movements among several short loops and adjoining secondary structural elements in the enzyme, most of which participate in dimer stabilization and formation of the active-site cleft. These rearrangements are similar to the ligand-binding-induced movements observed in globins and insulin and serve as a model for an enzymatic mechanism which involves local shifts of secondary structural elements during turnover, rather than large-scale domain closures or loop transitions induced by substrate binding such as those observed in hexokinase or triosephosphate isomerase.
About this Structure
1IKA is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Structure of isocitrate dehydrogenase with alpha-ketoglutarate at 2.7-A resolution: conformational changes induced by decarboxylation of isocitrate., Stoddard BL, Koshland DE Jr, Biochemistry. 1993 Sep 14;32(36):9317-22. PMID:8369301 Page seeded by OCA on Fri May 2 20:05:43 2008
